I will probably get flamed for this but I am going to post this anyways.
I am noticing a certain trend in Final Fantasy Boss encounters, especially the higher difficulty ones like Coil or Extreme Modes. It seems like that every encounter is designed as a slope that gets harder and harder the lower a Boss HP gets. Don't get me wrong there is nothing wrong with that if it is used here but this encounter design is starting to be used for every single battle in this game by now and it is starting to get annoying.
The only method of increased difficulty i have seen used in fights is either:
A. Put more of something (Ifrit Nails, Adds in T10, etc)
B. Put more damage on something that was already there (Charge in T10 cause of soft enrage, bahamuts claw, akh Morne and so on)
C. Change the fight by 180 Degrees from one point to the next without any logical transition (T5, T9 etc).
I get that you want to make encounters easier to learn but at the same time nobody wants to play 80% of a fight just so they get a 10 second window at the actual mechanic that causes them trouble just to do it all over again. Can't we have encounters that actually introduce you with the full fight mechanics right from the start or at least with 2 alternating phases? Can we please have some difficulty with the kind of sidejobs, or things to do beside the main role in the party throughout fights instead of just getting more of stuff and stronger stuff thrown at us?
TLDR;
Please stop your old Square Enix Pattern that you discovered in FFX for the first time (Seymoure anyone?) and try to design more interesting encounters instead of just piling on more of already existing things to simulate non existing difficulty.
Good Design:
T1, T4
Garuda Ex, Shiva Ex, Levi Ex, Mog Ex, Odin
T7, T8
Bad Design:
T2, T6,
Ifrit Ex
Pretty much every fight in FcoB
Horrible Design:
T5, T9